status-go/vendor/github.com/libp2p/go-openssl/sha256.go

90 lines
2.2 KiB
Go

// Copyright (C) 2017. See AUTHORS.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package openssl
// #include "shim.h"
import "C"
import (
"errors"
"runtime"
"unsafe"
)
type SHA256Hash struct {
ctx *C.EVP_MD_CTX
engine *Engine
}
func NewSHA256Hash() (*SHA256Hash, error) { return NewSHA256HashWithEngine(nil) }
func NewSHA256HashWithEngine(e *Engine) (*SHA256Hash, error) {
hash := &SHA256Hash{engine: e}
hash.ctx = C.X_EVP_MD_CTX_new()
if hash.ctx == nil {
return nil, errors.New("openssl: sha256: unable to allocate ctx")
}
runtime.SetFinalizer(hash, func(hash *SHA256Hash) { hash.Close() })
if err := hash.Reset(); err != nil {
return nil, err
}
return hash, nil
}
func (s *SHA256Hash) Close() {
if s.ctx != nil {
C.X_EVP_MD_CTX_free(s.ctx)
s.ctx = nil
}
}
func (s *SHA256Hash) Reset() error {
if C.X_EVP_DigestInit_ex(s.ctx, C.X_EVP_sha256(), engineRef(s.engine)) != 1 {
return errors.New("openssl: sha256: cannot init digest ctx")
}
return nil
}
func (s *SHA256Hash) Write(p []byte) (n int, err error) {
if len(p) == 0 {
return 0, nil
}
if C.X_EVP_DigestUpdate(s.ctx, unsafe.Pointer(&p[0]),
C.size_t(len(p))) != 1 {
return 0, errors.New("openssl: sha256: cannot update digest")
}
return len(p), nil
}
func (s *SHA256Hash) Sum() (result [32]byte, err error) {
if C.X_EVP_DigestFinal_ex(s.ctx,
(*C.uchar)(unsafe.Pointer(&result[0])), nil) != 1 {
return result, errors.New("openssl: sha256: cannot finalize ctx")
}
return result, s.Reset()
}
func SHA256(data []byte) (result [32]byte, err error) {
hash, err := NewSHA256Hash()
if err != nil {
return result, err
}
defer hash.Close()
if _, err := hash.Write(data); err != nil {
return result, err
}
return hash.Sum()
}